Understanding the role of haptoglobin in psoriasis: effects of ultraviolet B.

BACKGROUND: Haptoglobin (Hp) is one of the acute phase proteins, whose main function is to bind free haemoglobin (Hb) and transport it to the liver for degradation and iron recycling. In addition to its role as an Hb scavenger, Hp has been shown to behave as an anti-inflammatory, antioxidant and angiogenic factor. We previously investigated the role of Hp in the pathogenesis of psoriasis, and found that it displays some structural modifications that might be associated with protein function in the disease. Phototherapy is an efficacious treatment for psoriasis, although the biological mechanisms by which phototherapy improves psoriasis are still unclear. AIM: To investigate the effects of ultraviolet (UV)B on Hp to clarify the role of Hp in psoriasis. METHODS: Expression of the genes encoding Hp, interleukin (IL)-6 and IL-10 was assessed in UVB-irradiated and unirradiated HaCaT cells. The biological significance of Hp modulation of UVB treatment was confirmed by ELISA and Western blotting. The Hp gene and protein expression in the skin of patients with psoriasis was also investigated. RESULTS: In vitro results showed that UVB modulated IL-6 and IL-10 gene expression and Hp gene and protein expression in HaCaT cells. The in vivo data also showed that Hp levels were increased in the skin of patients with psoriasis compared with healthy controls. CONCLUSIONS: UVB irradiation was able to modulate Hp production in immortalized keratinocytes. The higher levels of Hp in vivo in both lesional and nonlesional skin suggest that it might have a role in the pathogenesis of the disease.

[Distribution of haptoglobin types and their significance in biochemical and immunologic indicators in persons exposed to low radiation doses]. / Raspredelenie tipov gaptoglobina i ikh znachenie v izmeneniiakh biokhimicheskikh i immunologicheskikh pokazatelei u liudei, obluchennykh v malykh dozakh.

Haptoglobin (Hp) polymorphism and its significance for changes in biochemical and immunological parameters was analyzed in personnel of a nuclear plant receiving doses of external and internal irradiation close to maximum permissible levels. The distribution of Hp types and frequencies of alleles Hp in the group of probands asa a whole (1-1 - 14.1%; 2-1 - 49.2%; and 2-2 - 36.7%) and in probands subjected to different types and doses of irradiation (1-1, 13.6 - 16.0%; 2-1, 47.8 - 50.5%; and 2-2:35.8 - 38.2%) did not differ from those expected or from corresponding parameters of the control group and population. An increase in the frequency of allele Hp was observed for persons over 60 years of age. It was found that the levels of uric acid, the activities of acid phosphatase, lactate dehydrogenase, alkaline phosphatase and its isozymes, and the content of certain lymphocyte classes and immune complexes are initially higher in carriers of Hp type 1-1. In these probands, changes in certain parameters related to irradiation were observed less frequently. In some cases, opposite changes in immunological parameters were observed in persons with different Hp types after internal irradiation.

Serum proteins in rats irradiated continuously over a long period at diminishing radiation dose rates.

The authors studied changes in serum protein concentrations in rats exposed 10 days to continuous irradiation at progressively diminishing dose rates imitating the radioactive decay of a fissile mixture, up to a total dose of 9 Gy, both during and up to 240 days after discontinuing irradiation. The prealbumin concentration (from the 6th day) and the A1-globulin concentration (from the 1st day) fell to 70% during irradiation. Afterwards, the A1-globulin level fell significantly up to the 28th day and then, from the 60th to the 240th day, rose again. During irradiation the serum haptoglobin concentration rose significantly from the 1st to the 10th day and the ceruloplasmin concentration on the 10th day. An increase in both protein concentrations (to 172% and 190%) was also observed on the 14th postirradiation day, after which the serum haptoglobin, ceruloplasmin and A1M concentration fell abruptly up to the 60th day.